Introduction

The modern technologies make it possible to carry out a secret nuclear weapon test practically at any point of the Globe. In this advanced conditions the monitoring of Comprehensive Test Ban Treaty (CTBT) demands designing of precise automated systems for registering and processing of a vast amount of multichannel data streams coming to data centers all over the world. The modern conceptions of CTBT monitoring give the significant function to small aperture seismic arrays (SASA) as the regional monitoring tool which provides autonomous detection, source location and identification of weak seismic events at regional distances.

Below we present a short description of an advanced computer technique for automated interactive processing of SASA data aimed to regional CTBT monitoring. The technique is developed at SYNAPSE Science Center and consists of Problem Oriented Programming Shell (POPS) for UNIX Workstations and an original program package for multichannel data analysis including the statistically optimal algorithms. Both components are combined in a special computer system which we name as SNDA (Seismic Network Data Analysis). The SNDA provides executing of all data processing stages needed for preliminary regional seismic bulletin issue using single SASA data: detection of seismic events, identification and parameter estimation of seismic phases, location of event sources and identification of its types. Note that the SNDA can be easily rearranged from small array data analysis to the automated monitoring processing of local seismic network recordings.

The SNDA comprises the most programming and graphic facilities which are implemented in the well known program packages for seismic monitoring with the help of a SASA, for example in the EP (Event Processing) System by NORSAR or in the IAS (Intelligent Array System) by SAIC. At the same time the SNDA possesses new features which make it more convenient for regional seismic monitoring under strong noise conditions. As the peculiarities of the SNDA we regard the following:

existence of an on-line subsystem providing a real time collection and pre-processing of a multichannel data;

wide use of the Data Stack (DS) concept (put forward in the EP System by NORSAR); DS is a tool for quick and flexible exchange of multichannel data between different SNDA subsystems and processing routines;

ability to easily generate a specific problem-oriented configuration of the system;

amicable user interface, which provides explicitly easy and quick installation in the SNDA of new user data analysis procedures;

availability of a Job Control Language (JCL) - a problem-oriented language which enables user to perform complex processing sessions realizing the Expert System strategy;

original graphic facilities, which comprise a graphic subsystem for multichannel interactive data analysis, a package for 2 and 3-dimensional graphic analysis and a package for graphic support of regional source location and identification procedures;

aptitude to read and save data disk files in the most conventional seismological formats such as CSS, SEED, SAC and NORSAR EP formats.